Method of and apparatus for producing glass fibers



Patented Sept. l, 1942 METHOD or AND APPARATUS Foa PaonUclNG GLAss mms Gedeon von Pazsiczky, Hamburg-Wandsbek, Germany, vested in the Alien Property Custodian Application November 6, 1939, Serial No. 303,059 In Germany November 15, 1938 7 Claims. (Cl. 49-1) The present invention relates to a method of and an apparatus for producing relatively flne fibers or filaments from molten glass, slag and other inorganic materials which are plastic when heated.

Heretofore various attempts have been made to produce glass fibers from molten glass utilizing centrifugal force as a factor in the attenuation of the fibers. Both the use of a perforated centrifugal drum and of a centrifugal disk have been resorted to for such a purpose and, from the point of view of the textile industry, satisfactory results have not been attained because of the inability of such devices to produce fibers that are ne enough for textile use. In particular, these known processes have the disadvantage that the centrifuging devices are too far removed from the source of molten glass so that the degree of fluidity of the glass is insuilicient for attenuation of ne fibers. The relatively coarse bers that are produced by such processes break easily and furthermore are accompanied by impurities such as globules of glass which hinder their use in textile machines.

'I'he present invention is designed to overcome the limitations that are attendant upon apparatus of this type utilizing centrifugal force as an attenuating factor and toward this end contemplates the centrifuglng of a rotatingliquid mass of molten glass over the edge of a rotating weir, the liquid mass being drawn directly from a supply body of the glass in close proximity thereto. In this manner molten glass of a higher temperature than has heretofore been possible is available for attenuation of the fibers.

The provision of an apparatus of the character set forth above being the principal object of the invention, lt is another object thereof to provide such an apparatus in which centrifugal force is utilized not only for attenuating the fibers from the rotating mass but is also utilized for elevating the glass to the level of the rotating weir in order that attenuation of the bers may take place from the edge of the weir.

A further object'of the invention is to provide an apparatus of this character in which the desired iluidity or viscosity of the glass may be insured by the use of a burner, the flame from which is directed against the surface of the rotating mass of molten glass in the vicinity of the region from which the fibers are attenuated.

It is another object of the invention, in a modified form thereof, to produce an attenuating apparatus in 4which the fibers are attenuated by tially to throw the fibers radially outwardly with the bers assuming in their movement a substantially spiral path, and in which additionally other centrifugal forces subsequently act upon the ilbers to change their direction of movement and further attenuate the same with the bers assuming movement in a reverse spiral direction.

Other objects and advantages of the invention, not at this time enumerated, will become apparent as the following description ensues.

In the accompanying single sheet of drawings:

Fig. 1 is a vertical sectional view taken substantially centrally through a centrifugal attenuating apparatus constructed in accordance with the principles of the present invention;

Fig. 2 is a sectional view taken substantially along the line 2 2 of Fig. 1;v and Fig. 3 is a sectional view similar to Fig. 1 showing a 'modified form of apparatus.

Referring now to Fig. 1, a supply tank Il adapted to .contain a supply body G of molten glass is provided with an opening I2 in the top wall thereof. A funnel-shaped centrifuging member I4 the walls of which are flared outwardly as at I6 adjacent the upper edge thereof beyond thenormal taper of the walls is rotatably mounted in the opening I2 on bearings I8 and the lower small end thereof extends below the level of the glass G in the tank I0. A series of spaced ribs 20 are formed on the inner tapered surface of the member I4 and extend from the bottom thereof to the upper edge thereof. A ring member 22 maintains the member I4 seated on the bearings I8 while a chain and sprocket mechanism 24 effects rotation of the member at relatively high speed.

Air introduced into the tank I0 vfrom a conduit 26 serves to force the molten glass at least partially upwardly in the rotating member I4 while the centrifugal force acting upon the glass by virtue of the rotation of the former carries centrifugal forces that act upon the same inithe glass upwardly in the form of a rotating cone as indicated at 28 in such a manner that the glass is flung radially outwardly over the upper edge of the member I4, which in eifect constitutes a rotating Weir, and the glass is thus attenuated and drawn into fine filaments which, when acted upon by the relatively quiescent air surrounding the member I4 causes the filaments to progress outwardly in spiral fashion. The attenuated fibers will build up in the form of a 1ring and they may be thus collected in` this orm.

A hood 30 overlies the member I4 and a burner 32 extending downwardly through the hood 30 applies a llame to the glass contained within the member I4 to maintain the same at a sulciently high temperature that the glassv will have the desired degree of viscosity for proper attenuation of ne ilbers over the edge of the rotating Weir.

It is to be noted that the main supply body of glass G within the tank I is relatively close to the region of attenuation and therefore the temperature dropin the glass prior to attenu-.f ation of fibers therefrom is no more than desired. However, any excessive temperature drop may be compensated for by the provision of the burner 32. In certain instances however the use of the burner 32 may be dispensed with. For these reasons the production of bers of relatively small diameters is made possible.V

In Fig. 3 a modified form of construction is shown in which the central rotating centrifuging member H4 is surrounded by a second and concentric centrifuging member |34 mounted in bearings v|315 and driven by means of a chain and sprocket mechanism |38 in a direction opposte to the direction of rotation of the central member H4. The central centrifuging member ||4 is maintained seated upon its bearings H8 by means of a spider |41) connected to a vertical shaft |42 by means of which the member ||4 is rotated. The shaft v|42 extends through a sleeve |32 corresponding to the burner -air to the attenuating region while a'ir intro duced through the conduit |26 serves to force the glass upwardly into the rotating member III.

It is to be noted that the elevation of the upper edge of the outer centrifuging member |34 is slightly above the level of the upper edge of the centrifuging member H4 and thus the filaments which are attenuated in a spiral di'- rection from this latter edge are subsequently engaged by the'former edge and are further attenuated in a spiral direction which is oppositely directed with respect to the first direction. In this manner, not only are fibers of very small diameters produced, but the surrounding circular region in which the fibers are collected is materially reduced in diameter.

Modifications may be resorted to within the spirit and scope of the appended claims.

I claim:

1 Apparatus for producing fibrous glass comprising a tank containing a pool of molten glass, a substantially vertically disposed centrifuging' member open at its upper and lower ends and having an outwardly and upwardly tapered conical inner wall, means supporting the member for rotation about a vertical axis with its lower end submerged in the pool, means for rotating the member in one direction, a second centrifuging member surrounding the iirst member, said second member also having an outwardly and upwardly tapered conical inner wall terminating in an upper edge that is slightly higher than the upper end of the rst centrifuging member,

site to the direction o! rotation of the first member.

filaments from molten glass which comprises establishing a stationary supply body of molten glass, causing a mass of molten glass to be drawn upwardly from the supply body and Vmove by centrifugal force as a layer over the interior' surface of a rotating open-ended vertically disposed hollow centrifuging member submerged partly in said supply body, while maintaining the continuity of said mass of molten glass with said supply body, and causing the layer of molten glass within the member to be reduced in thickness as it moves upwardly and be thrown outwardly vfrom the upper edge of the member into the atmosphere to be thereby attenuated into ne fibers.

3. The method of producing relatively line filaments from molten glass which comprises maintaining a stationary supply body of molten glass, causing a mass of molten glass to be drawn upwardly from the supply body and move by centrifugal force as a layer over theinterior surface of a rotating open-ended vertically disposed hollow centrifuging member above said supply body and partly submerged therein, while maintaining the continuity of said mass ofV molten means supporting the second member for rotation about a vertical axis, and means for rotating the second member in a direction oppo- 75 glass with said supply body, and -causing the layer of molten glass within the memberl to be reduced in thickness as it moves upwardly and be thrown outwardly from the upper edge of the member into surrounding atmosphere while si- Y multaneously applying heatto the mass of glass within the centrifuging member, thereby attenuating the glass into ne bers.

4. Apparatus for producing brous glass comprising a tankA adapted to contain a pool of molten glass, a vertically disposed centriiuging member provided with upper and lower open ends and having an outwardly and upwardly tapered annular inner wall, said wall having an increased outward taper at its uppervend forming a ared portion and said wallterminating at the top of the member in an overilow edge, means for supporting the memberrotatably about a vertical axis with its lower end submerged in the molten glass in the pool. and its top open to the atmosphere and means for rotating the member to cause the molten glass to move upwardly over the tapered annular surface and be acceleratedl by said ilared portion and then thrown centrifugally from the upper edge of said member into surrounding'atmosphere, thereby attenuating the glass into-laments. Y

v5. Apparatus for producing iibrous glass comprising a tank containing a -pool of molten glass,

a vertically disposed centrifuging member having open top and bottom and an outwardly and upwardly tapered annular inner wall, said member terminating at the top thereof in an overflow edge, means supporting the member for rotation about a vertical axis with' its top .open to the atmosphere and its bottomv submerged in the molten glass contained in the pool, and

means for rotating the member to cause the molten glass to move progressively upwardly over the tapered wall and be thrown centrifugally ber having an open bottom and an outwardly and upwardly tapered .annular inner wall, the

2. The .method or producing relatively tine top of said member being formed as an overow edge, a series of ribs formed onsaid wall extending in a generally vertical direction and projecting inwardly from the wall, means supporting the member for rotation about a vertical axis with its bottom submerged in the molten glass contained in the pool and its top open to the atmosphere, and means for rotating the member to cause the molten glass to move progressively upwardly over the tapered wall and be thrown centrifugally from the overow edge of the member.

'7. Apparatus for producing fibrous glass comprising a tank containing a pool of molten glass, a vertically disposed open-ended centrifuging pered annular inner wall, said membel` terminating at the top of the tapered wall in an overflow edge, means supporting the member for rotation about a vertical axis with its bottom submerged in the molten glass contained in the pool, means for rotating the member to cause the mo1- ten glass to move upwardly over the tapered wall and be thrown outwardly from the overflow edge of the member, a hood overlying the member and spaced from said edge, and a burner Within the hood directed downwardly into the member for applying heat to the glass COIltained within the member.

GEDEON VON PAZSICZKY. 

